Odds of Death by Asteroid? Lower Than Plane Crash, Higher Than Lightning

Share

Odds of Death by Asteroid? Lower Than Plane Crash, Higher Than Lightning

Don Davis/NASA

Most people in the U.S. woke up to a spectacular sight this morning: videos from Russian dashboard cameras showing a fireball in the sky crashing down to the Earth. The 15-meter meteorite impacted the atmosphere and exploded above the Chelyabinsk region of central Russia, injuring an estimated 1,200 people and causing roughly 1 billion rubles ($33 million U.S.) in damage. It was the largest meteorite to hit the country in more than a century.

Throughout its 4-billion-year history, the Earth has been hit by millions of asteroids, many over 1 kilometer in diameter and capable of widespread havoc. But most of these asteroids hit early in our planet's history, when the solar system was young and rogue space rocks far more common. Because of the constant churning of the Earth's mantle that devours old crust, only about 160 surviving impact craters remain on the planet's surface. These days, very large impacts are not expected to happen more than once every few million years.

Asteroid Size

Frequency

Damage Potential

1 micron

Every 30 microseconds

Burns up in atmosphere

1 millimeter

Every 30 seconds

Burns up in atmosphere

1 meter

Every year

Tiny burst in air, no piece reaches ground

10 meters

Every 10 years

Moderate burst in air, some fragments may reach ground. The bolide that hit Russia on Feb. 15 was estimated to be 15 meters across.

100 meters

Every 1,000 years

Enormous burst in air, leveling large area, equivalent to a thermonuclear hydrogen bomb. Tunguska impact that hit a remote part of Russia in 1908 was one of these.

10 kilometers

Every 100 million years

Gigantic planet-wide destruction, mass extinction, enormous crater. The Chicxulub impactor that killed the dinosaurs was one of these.

The other good news is that modern humans are looking out for potentially hazardous asteroids. NASA's Near Earth Object program has a risk table for all known objects that calculates their likelihood of impact for the next 100 years. Asteroids are plotted on the Torino Scale, which runs from 1 to 10 to assess the menace we face from any asteroid. Currently, nothing on the table is above a 1, which means it poses no level of danger and an impact is calculated as extremely unlikely. With new private outfits like the B612 Foundation hoping to launch a dedicated telescope to discover 90 percent of all asteroids more than 30-meters in diameter, humanity is on the case.